This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this project, NIR fluorophores are quantified in solution. The excitation and emission spectra as well as the quantum yield are measured in solution using a fluorimeter housed at the LFD.